Precipitate formation in austenitic stainless steel welds

Journal Article · Fri Feb 01 04:00:00 EST 1985 · Scr. Metall.; (United States)

DOI:https://doi.org/10.1016/0036-9748(85)90174-7· OSTI ID:6325069

Cieslak, M J; Ritter, A M

Recent research efforts have revealed many of the factors which control the hotcracking susceptibility of austenitic stainless steel weld metals. It is generally agreed that the segregation of impurity elements to solidification grain boundaries is a primary cause of the hot-cracking tendency of these alloys in that elements such as phosphorus and sulfur form low melting point eutectics with the metal matrix. Furthermore, these elements can also degrade cracking resistance by lowering the surface tension of the interdendritic fluids to which they segregate. In the case of phosphide precipitation in austenitic stainless steel weld metal, there is apparently some question in the literature as to the specific phosphide formed. This study was undertaken to determine the microstructural relationships, relative to phosphide formation, pertaining to hot-cracking of austenitic stainless steel weld metals. The results confirm that phosphides of the type (Fe, Cr)/sub 3/P form in austenitic stainless steel welds. These phosphides appear at both eutecticferrite/austenite interfaces and along solidification hot-cracks, where they most likely form via an eutectic reaction. These results are inconsistent with those of Brooks et al. in that no evidence of either the MP or MP/sub 3/ phosphide was found. No reference could be found, either in the published literature or in standard compilations of crystallographic information, to verify the existence of a CrP/sub 3/ phase, suggesting that the theory of chromium depletion (CrP/sub 3/ vs. CrS) needs further substantiation before it is accepted.

• Research Organization: Sandia National Laboratories, Albuquerque, NM
• OSTI ID: 6325069
• Journal Information: Scr. Metall.; (United States), Journal Name: Scr. Metall.; (United States) Vol. 19:2; ISSN SCRMB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
AUSTENITIC STEELS
CHEMICAL REACTION KINETICS
CHROMIUM ALLOYS
CHROMIUM COMPOUNDS
CORROSION RESISTANT ALLOYS
CRACKS
CRYSTALLIZATION
FABRICATION
FRACTURE PROPERTIES
IRON ALLOYS
IRON BASE ALLOYS
IRON COMPOUNDS
IRON PHOSPHIDES
JOINING
JOINTS
KINETICS
MECHANICAL PROPERTIES
PHASE TRANSFORMATIONS
PHOSPHIDES
PHOSPHORUS COMPOUNDS
PNICTIDES
PRECIPITATION
REACTION KINETICS
SEPARATION PROCESSES
STAINLESS STEELS
STEELS
TRANSITION ELEMENT COMPOUNDS
WELDED JOINTS
WELDING